The placenta plays an important role in the development and maintenance of pregnancy, as well as fetal growth and health. During pregnancy, the thin tissue layer that separates the maternal and fetal circulations is known as the placental barrier. This maternal-fetal interface in the human placenta regulates the exchange of nutrients, gases, metabolic waste, and xenobiotics between the intervillous space and fetal capillaries. In particular, in the chorionic villi of third trimester placenta, the maternal and fetal circulations are brought in close proximity to facilitate efficient exchange of various substances. (FIG. 1.)
As such, attempts have been made to study maternal-fetal transfer. (FIG. 2) However, such attempts have faced a variety of technical challenges. For example, in vivo animal models can be limited by interspecies differences and ex vivo perfusion of placental tissue is hampered by the limited length of time the tissue remains viable. While in vitro methods for studying maternal-fetal transport have been developed, e.g., culture of trophoblasts on semipermeable transwell supports, certain tissue culture platforms cannot be readily used for co-culture of two cell types and can be limited in their ability to recapitulate complex three-dimensional structure and dynamic mechanical and biochemical microenvironments that can play a role in health and disease.
Therefore, there is a need for a low-cost, human cell-based alternative to current maternal-fetal transfer models. Additionally, there is a need for a model that has improved parametric spatiotemporal control over the interaction of cells with their culture substrates, neighboring cells, and surrounding environment.